Miniature switches of the rocking contact type



Oct. 31, 1967 H. w. BROWN 3,3 0,

MINIATURE SWITCHES OF THE ROCKING CONTACT TYPE Filed Dec. 5, 1964 I 5Sheets-Sheet l 31, 1967 H. w. BROWN 3,350,521

MINIATURE SWITCHES OF THE ROCKING CONTACT TYPE Filed D90. 5, 1964 5Sheets-Sheet 2 Oct. 31, 1967 H. w. BROWN 3,350,521

MINIATURE SWITCHES OF THE ROCKING CONTACT TYPE Fil'ed Dec. 5, 1964 3Sheets-Sheet 3 3,350,521 MINIATURE SWITCHES OF THE ROCKING CONTACT TYPEHarry W.'Brown, Big Bend, Wis., assignor to Cutler- Hammer, Inc.,Milwaukee, Wis., a corporation of Delaware Filed Dec. 3, 1964, Ser. No.415,676 7 Claims. (Cl. 200-67) This invention relates to miniatureswitches and more particularlyto miniature switches of the manuallyoperable type. I

While not limited thereto, the invention is especially applicable tominiature switches of the toggle lever actuated type.

' An object of the invention is to provide improved miniature switches.

A more'specific object of the invention is to provide improved switchstructure which adapts it for miniaturization and affords superiormechanical and electrical characteristics.

Another specific object of the invention is to provide an improvedsingle pole toggle lever switch especially adapted for miniaturization.

Another specific object of the inventionis' to provide an improveddouble pole toggle leverswitch especially adapted for miniaturization.

Other objects and advantages of the invention will hereinafter appear.These and other objects and advantages of the invention and the mannerof obtaining them will best be understood by reference to'the followingdescription of embodiments thereof taken in conjunction with-theaccompanying drawings, wherein:

FIGURE 1' is an isometric view of a single pole toggle lever switchconstructed in accordance with the invention;

FIG. 2 is an enlarged cross-sectional viewof the switch of FIG. 1 takenalong line 2-2 of 'FIG.3;

FIG. 3 is a view partly in section taken along line 3-3 of FIG. 2;'

FIG. 4 is an exploded isometric view of the parts of the switch'of FIGS.1-3;

FIG. 5 is an isometric view of a double pole toggle lever switchconstructed in accordance with the invention; a

FIG. 6 is an enlarged cross-sectional view of FIG. 5 taken along line6-6 of FIG. 7; 7

FIG. 7 is a view partly in section taken along line 7-7 of FIG. 6;

FIG. 8 shows a front elevational view of'the actuator of the switch ofFIGS. 5-7; I

of the switch and FIG. shows an exploded isometric view of the parts ofthe switch of FIGS. 5-9.

Referring to FIGS. 1-4, there are shown thephysical characteristics of asingle-pole double-throw, toggle lever FIG. 9 showsa top view of theactuator of FIG. 8;

3,350,521 Patented Oct. 31, 1967 top being open. The open sides of thebase portions face one another with the edges of the end walls andbottom walls thereof abutting and are clamped in this position by 2switch frame 6 which also covers the open top of the ase.

As shown in the exploded view in FIG. 4, the bottom of each base portion2 is provided with three spaced notches or apertures including a centeraperture 2a and relatively narrow apertures 2b on either side thereof.The three apertures in the opposite base portions are respectively inalinement with and connect with each other for clamping a contactsupport terminal 8 in the central aperture and for clamping contactterminals 10 and 11 in the side apertures. The side wall is providedwith three vertical grooves including a groove 20 opposite aperture 2aand relatively narrow grooves 2d opposite apertures 2b for anchoringlateral projections of the contact terminals. These contact terminals 10and 11 are provided with a generally T-shaped upper end or contactportion and the ends of the cross on the T constitute the lateralprojections 10a and 11a which enter the narrow grooves 2d. Therelatively wider center groove 20 is provided to anchor contact supportterminals of the type hereinafter described in connection with FIGS.5-10.

Contact terminals 10 and 11 shown in FIG. 4 are provided with slots 10band 11b in opposite edges thereof at about the midportion which passthrough the apertures in the bottom of the base for securely fixing thecontact terminals to the base when the two halves thereof are clampedtogether. Contact terminals 10 and 11 are similar to one another exceptthat the latter has a higher contact portion as shown in FIG. 2 toprovide momentary-on switch operation. Contact support terminal 8 isprovided with similar slots 8a in opposite edges thereof for fixing thesame in the center aperture 2a between the base halves. As shown in FIG.2, contact support terminal 8 is formed of a metal strap bent double inthe middle and having its ends bent outwardly and then upwardly to forma supporting cradle for movable contactor 12. The opposite sides of suchcradle, that is, the ends of the metal strap are provided with slots 8bto allow rocking of the movable, contactor thereon. While terminal -8 ispreferably made from a single strap, it could be made of two pieces notconnected at the lower ends.

Movable contactor 12 is a metal strap having lateral extensions 12a onopposite edges at its midportion for retaining it in the cradle of thecontact support terminal 8. Contactor 12 also is suitably bent at itsmiddle so that the two halves thereof are at upward angles and areseparated from-contact terminals 10 and 11 when, the switch 'is in itsoff position as shown in FIG. 2. V Actuator 14 has a generally V-shapedrunner with a flat horizontal upper surface which is provided with ahole f'orreceiving the reduced lower end portion 16a .of a plunger pin16. The lower runner portion of actuator 14 is reduced in thickness sothat it can be freely moved rounded enlarged, portion 18a near its lowerend for pivotally supporting it in bushing 22. For this purpose, the

upper end of the hole in bushing 22 is provided with a constrictionformed by an internal rib 22a against which the enlarged portion of theoperating lever bears under the force of spring 20 and on which itpivots upon movement of the operating lever. Bushing 22 is threaded onthe outside and is provided with a keyway 22b to facilitate mounting ofthe switch in an aperture in a panel. Bushing 22 is rigidly secured atits lower end into a central hole in switch frame 6 as by peening athinned end of the bushing against the inner edge of the hole as shownin FIG. 2.

Switch frame 6 is a sheet metal punching in the shape of a strap buthaving side flaps 6a on opposite sides of its midportion formed bybending lateral portions thereof downwardly. The upper portions of thetwo halves of switch base 2 snugly fit between these flaps and are heldtogether thereby. The opposite end portions of the switch frame 6 arebent downwardly along the ends of the base and are provided with pairsof lateral ears 6b which may be bent around the corners of the base andagainst the opposite sides thereof as shown in FIG. 1. As shown in FIGS.1, 3 and 4, each base portion is provided on its outer side with adepression at the top for receiving the corresponding side flap 6a and apair of depressions at its lower corners for receiving lateral ears 6bof the switch frame.

The double-pole modifications shown in FIGS. -10 uses some parts likethose in the single-pole switch hereinbefore described and these partshave been given like reference characters. However, it is apparent thatthe base has an added part to provide two cavities or compartments forthe two poles of the switch. A double actuator also is used and theswitch frame is wider to encompass the thicker base.

As shown in FIGS. 5 and 10, a central base portion 24 is placed betweenlike base portions 2, the latter being identical to those used in thesingle pole switch. The central base portion 24 has two end walls, abottom wall and a dividing wall upstanding from the bottom. Thisdividing wall is only about one-half the height of the end walls sincethe actuator must extend thereover to engage both movable contactors. Asshown in FIG. 10, the bottom of base portion 24 is provided on oppositesides of the dividing wall with center notches or apertures 24a andrelatively narrow notches or apertures 24b on opposite sides thereof forreceiving contact support terminal 26 and contact terminals 10 and 28.As will be apparent, these apertures in the central base portion arerespectively in alinement with apertures 2a and 2b in base portions 2whereby to clamp the contact terminals therebetween. Central baseportion 24 is also provided with vertical grooves 240 and 24d onopposite surfaces of the dividing wall for receiving and anchoring thelateral projections such as 10a and 28a of the stationary contacts.

It will be recalled that the single pole switch in FIGS. 1-4 wasillustrated and described as having a cradle type of center contactsupport terminal 8. This cradle provides a center off position and canbe used in either the single-pole or double-pole switch. To show avariatlon in switch operation, the double-pole switch in FIGS. 5-10 hasbeen illustrated as having a flat contact support terminal 26 which isused when a center position for the operating lever is not desired. Thisdouble-pole switch is illustrated as having an on position on one sideand a momentary on position on the other side and no center offposition. For this purpose, contact support terminal 26 is thicker thanthe other contact terminals 10 and 28 on either side thereof but isflat. It is provided with slots 26a on opposite edges at its midportionwhereby it is gripped by base portions 2 and 24. Its upper end isprovided with a slot 26b for receiving a modified movable contactor 30for rocking movement thereon. Movable contactor 30 is in the form of ametal strap having two pairs of lateral projections 30a spaced from oneanother to provide side slots therebetween. As will be apparent, the

narrow portion of contact 30 between the pairs of projections entersinto slot 26b in contact support 26 and the pairs of projections retainit thereon. The slots between the pairs of projections 30a are widerthan the thickness of contact support terminal 26 to allow the contactorto rock freely thereon.

Contact terminal 28 is like contact terminal 10 except that the uppercontact portion thereof is higher. Since the pivot point of the movablecontactor is higher in FIG. 6 than it is in FIG. 2 to avoid a center offposition, the stationary contact 28 must also be higher to provide formomentary action, that is, to cause reopening of the switch when theoperating lever is released.

As shown in FIGS. 8-10, actuator 32 is designed to straddle the dividingwall in the base and is provided with a pair of generally V-shapedrunners 32a for sliding along the respective movable contactors 30,these runners being connected by a horizontal flat portion extendingacross the dividing wall. The vertical hole in the center of actuator 32is elongated or oval in shape as shown in FIG. 9 to allow the actuatorto rock a limited amount on the reduced lower end portion 16a of pin 16as depicted by dotted lines in FIG. 8. Also, a pair of rounded beads 32bare molded on the upper surface of the actuator, one on each side of thehole and immediately adjacent thereto. These beads bear against theshoulder on pin 16 to facilitate rocking of the actuator on the pin. Aswill be apparent, this rocking allowance of the actuator insurespositive pressure engagement thereof against both movable contactorsunder the force of the compression spring which is inside the operatinglever. This pressure engagement insures closing of the contacts andavoids any condition where one pole closes and the other pole is heldopen due to binding of the parts.

Switch frame 34 is similar to that in FIGS. l-4 except that it is widerto embrace and cover the thicker base in the double-pole switch.

While the single-pole switch of FIGS. 1-4 has been illustrated as havingon and momentary on operating positions and a center off position andthe doublepole switch of FIGS. 5-10 has been shown as having on andmomentary on operating positions with no center position, it will beapparent that other combinations of operating positions are possible.Any combination of on, momentary on, off and center none positions maybe provided by selecting proper contact terminals and central contactsupport terminals of the type shown in FIGS. 4 and 10 and by selecting asuitably bent movable contactor to fit the center contact supportterminal used in each particular case.

The switches hereinbefore described are constructed so that they areespecially adapted for miniaturization. For example, these switches canbe constructed so that they are only about 1% inches high overall. Thesinglepole switch at its frame may be only about one half inch long anda quarter inch wide. The double-pole switch at its frame may also beonly about a half inch long and slightly less than a half inch wide.These small dimensions provide a switch that has a capacity of 5 amperesat volts alternating current.

The characteristics which afford the aforementioned miniaturization andelectrical capacity reside in the structural features and thecombination thereof hereinbefore illustrated and described. For example,the contact terminals and the contact support terminals are capable ofcarrying a large current relative to their size since no rivets arerequired to connect the contact portions thereof to their externalterminal portions. This is brought about by the shape and arrangementthereof whereby the contact terminals and contact support terminals areclamped between portions of the insulating base. The elimination ofriveting in contact support terminal 8 is derived from its bent-doublestructure whereby a cradle for the movable contractor is provided by aforming operation alone. The arrangement of the actuator, pin andoperating lever and spring therein of both the single-pole anddoublepole switches provides operating means of minimum height for atoggle lever switch while also affording sufficient contact pressurewhen the contacts are closed. The symmetrical construction of the baseand the design of switch frame which holds all of the parts togetherfurther, contribute to the advantageous features hereinbefore described.

While the invention hereinbefore described is effectively adapted tofulfill the objects stated, it is to be understood that I do not intendto confine my invention to the particular preferred embodiments ofminiature switches disclosed, inasmuch as they are susceptible ofvarious modifications without departing from the scope of the appendedclaims.

I claim:

1. In an electric switch especially adapted for miniaturization:

a housing provided with a contact cavity;

a pair of spaced stationary contacts in said cavity and having terminalportions extending through a wall of the housing;

a movable contact arranged to be rocked in opposite directions to engageat either end portion thereof one or the other of said stationarycontacts;

actuator means for rocking said movable contact;

and means for performing the combined functions of supporting saidmovable contact for rocking movement and forming a common connectorarranged to be electrically connected to either one of said stationarycontacts when said movable contact is rocked without use of connectingmeans such as rivets or the like;

said means comprising current conducting strips lying flat against oneanother for a portion of their length and extending through a wall ofthe housing to provide an external terminal;

the portions of said strips within the housing cavity being bent awayfrom one another and then bent parallel to one another and to the firstportions thereof and being formed to provide a cradle for said movablecontact.

2. The invention defined in claim 1, wherein said parallel portions areprovided with notches for receiving said movable contact.

3. In an electric switch especially adapted for miniaturization:

an insulating housing formed of at least two complementary portions toprovide a contact cavity therein;

a pair of spaced stationary contacts formed of flat strips gripped inslots between said housing portions to provide contact portions in saidcavity and terminal portions outside the housing;

a movable contact arranged to be rocked in opposite directions to engageat either end thereof one or the other of said stationary contacts;

actuator means for rocking said movable contact;

and means for performing the combined functions of supporting saidmovable contact for rocking movement and forming a common connectorcomprising:

a current conductor strip folded at its middle and having its endportions bent away from one another and then bent parallel to the foldedportion to extend in a direction away from the latter thereby to form asubstantially U-shaped cradle the tips of which have cut-out portionsfor receiving said movable contact within said cavity and said foldedportion extending outside the housing to provide a terminal, saidcurrent conductor strip being aunitary member capable of carrying alarge current for its small size since it does not require rivet holesor the like;

and said movable contact being provided with lateral projectionsextending between the legs of said U- shaped cradle to retain themovable contact therein but to permit rocking to engage either one ofsaid stationary contacts.

4. In a miniature electric switch adapted to carry a relatively largecurrentfor its small size:

an insulating housing formed of two symmetrical,

complementary portions abutting one another to provide a compartmenttherein open at the top and having alined notches in the abuttingportions of the bottom forming apertures therethrough;

at least two spaced stationary contact-terminals formed of flat stripsclamped in said notches between said housing portions to providecontacts in said compartment and integral terminals outside the housing;

a movable contact arranged to be rocked in opposite directions withinsaid compartment to engage one of said stationary contacts;

means on the other stationary contact for pivotally supporting saidmovable contact for said rocking movement comprising layers of saidother stationary contact bent apart to form a cradle for said movablecontact, said cradle and integral external terminal being a unitarymember performing the combined functions of supporting said movablecontact and forming an external connector;

and means for rocking said movable contact comprisan actuator slidableon said movable contact;

a manually operable toggle lever;

and a spring biased plunger pin at the lower end of said toggle leverhaving a reduced end portion extending into a hole in said actuator;

and a switch frame clamping said housing portions together and includinga bushing in which said toggle lever is pivotally supported.

5. The invention defined in claim 4, wherein:

said housing comprises grooves on the interior walls thereof adapted toreceive contact-terminals of different heights;

and lateral projections on said contact-terminals anchored in saidgrooves.

6. In a miniature electric switch constructed so that it will have arelatively large current capacity for its small size:

an insulating housing formed of two symmetrical outer portions abuttingopposite sides of a center portion, said center portion having adividing wall forming two compartments open at the top and open into oneanother above said dividing wall, said portions having alined notches inthe abutting portions of the bottom;

stationary contact-terminals clamped in said notches between saidhousing portions to provide contacts in said compartments andrespectively integral terminals outside the housing; movable contactsarranged to be rocked in opposite directions within the respectivecompartments to engage a stationary contact in each said compartment;

means on the other stationary contacts in the respective compartmentsfor pivotally supporting the respective movable contacts for rockingmovement comprising two layers of which each said other stationarycontact is formed and being bent outwardly and then upwardly to form aseat for rockably supporting the associated movable contact, said seatand integral terminal being a unitary device requiring no rivets or thelike which would reduce its current capacity;

and means for rocking said movable contacts comprisan actuatorstraddling said dividing wall and having depending runners slidable onsaid movable contacts;

a manually operable toggle lever having a bore therein opening at itslower end;

a spring biased plunger pin extending from said bore and having areduced end portion;

and a hole in said actuator for said reduced end portion of said pin andbeing larger than the latter but smaller than the remainder of said pinwhereby the shoulder on said pin bears against said actuator and thelatter is freely rockable a limited amount to insure pressure engagementwith both movable contacts.

7. The invention defined in claim 6, wherein said actuator comprises:

rounded beads in its upper surface on opposite sides of saidv hole andbearing against the shoulder of said pin to enhance rocking of saidactuator on said shoulder.

References Cited UNITED STATES PATENTS Meuer 20068 X Dietrich 20068Obszarny 200--68,X Lauder et a1.

Heusser 200-68 Ludwig. Anderson.

ROBERT K. SCI-IAEFER, Primary Examiner.

D. SMITH, JR., Assistant Examiner.

1. IN AN ELECTRIC SWITCH ESPECIALLY ADAPTED FOR MINIATURIZATION: AHOUSING PROVIDED WITH A CONTACT CAVITY; A PAIR OF SPACED STATIONARYCONTACTS IN SAID CAVITY AND HAVING TERMINAL PORTIONS EXTENDING THROUGH AWALL OF THE HOUSING; A MOVABLE CONTACT ARRANGED TO BE ROCKED IN OPPOSITEDIRECTIONS TO ENGAGE AT EITHER END PORTION THEREOF ONE OR THE OTHER OFSAID STATIONARY CONTACTS; ACTUATOR MEANS FOR ROCKING SAID MOVABLECONTACT; AND MEANS FOR PERFORMING THE COMBINED FUNCTIONS OF SUPPORTINGSAID MOVABLE CONTACT FOR ROCKING MOVEMENT AND FORMING A COMMON CONNECTORARRANGED TO BE ELECTRICALLY CONNECTED TO EITHER ONE OF SAID STATIONARYCONTACTS WHEN SAID MOVABLE CONTACT IS ROCKED WITHOUT USE OF CONNECTINGMEANS SUCH AS RIVETS OR THE LIKE, SAID MEANS COMPRISING CURRENTCONDUCTING STRIPS LYING FLAT AGAINST ONE ANOTHER FOR A PORTION OF THEIRLENGTH AND EXTENDING THROUGH A WALL OF THE HOUSING TO PROVIDE ANEXTERNAL TERMINAL;